Abstract
DG81 is a cDNA clone derived from a subtracted library containing those RNA molecules that are present in gastrulae but absent from eggs of the frog Xenopus laevis. DG RNAs (where DG indicates differentially expressed in gastrula) represent the products of new transcription activated in the embryo at the midblastula transition or shortly thereafter. DG81 RNA is first detected in middle to late gastrulae, peaks in abundance in early tadpoles, and declines to background levels by the end of metamorphosis. Sequence analysis of an almost full-length cDNA clone homologous to DG81 allows deduction of a protein sequence that shows extensive homology to known intermediate filament proteins, most notably to epidermal type I cytokeratins. Consequently, the protein encoded by DG81 has been named XK81, for Xenopus keratin 81. In concert with keratins analyzed previously, XK81 has a central coiled-coil alpha-helical domain of 312 amino acids, which accounts for most of the homology to other keratins. This rod-like region is flanked by more divergent domains of 73 amino acids at the NH2 terminus and 44 amino acids at the COOH terminus. XK81 provides an example of a cytokeratin whose expression is limited to pre-adult developmental stages. We suggest that XK81 functions specifically in the differentiation of the tadpole epidermis.
Full text
PDF




Images in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Aviv H., Leder P. Purification of biologically active globin messenger RNA by chromatography on oligothymidylic acid-cellulose. Proc Natl Acad Sci U S A. 1972 Jun;69(6):1408–1412. doi: 10.1073/pnas.69.6.1408. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bailey J. M., Davidson N. Methylmercury as a reversible denaturing agent for agarose gel electrophoresis. Anal Biochem. 1976 Jan;70(1):75–85. doi: 10.1016/s0003-2697(76)80049-8. [DOI] [PubMed] [Google Scholar]
- Banks-Schlegel S. P. Keratin alterations during embryonic epidermal differentiation: a presage of adult epidermal maturation. J Cell Biol. 1982 Jun;93(3):551–559. doi: 10.1083/jcb.93.3.551. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Boros I., Pósfai G., Venetianer P. High-copy-number derivatives of the plasmid cloning vector pBR322. Gene. 1984 Oct;30(1-3):257–260. doi: 10.1016/0378-1119(84)90130-6. [DOI] [PubMed] [Google Scholar]
- Chirgwin J. M., Przybyla A. E., MacDonald R. J., Rutter W. J. Isolation of biologically active ribonucleic acid from sources enriched in ribonuclease. Biochemistry. 1979 Nov 27;18(24):5294–5299. doi: 10.1021/bi00591a005. [DOI] [PubMed] [Google Scholar]
- Church G. M., Gilbert W. Genomic sequencing. Proc Natl Acad Sci U S A. 1984 Apr;81(7):1991–1995. doi: 10.1073/pnas.81.7.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Davidson E. H., Hough B. R. Genetic information in oocyte RNA. J Mol Biol. 1971 Mar 28;56(3):491–506. doi: 10.1016/0022-2836(71)90396-2. [DOI] [PubMed] [Google Scholar]
- Dworkin M. B., Shrutkowski A., Baumgarten M., Dworkin-Rastl E. The accumulation of prominent tadpole mRNAs occurs at the beginning of neurulation in Xenopus laevis embryos. Dev Biol. 1984 Dec;106(2):289–295. doi: 10.1016/0012-1606(84)90227-6. [DOI] [PubMed] [Google Scholar]
- Eichner R., Bonitz P., Sun T. T. Classification of epidermal keratins according to their immunoreactivity, isoelectric point, and mode of expression. J Cell Biol. 1984 Apr;98(4):1388–1396. doi: 10.1083/jcb.98.4.1388. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Franz J. K., Gall L., Williams M. A., Picheral B., Franke W. W. Intermediate-size filaments in a germ cell: Expression of cytokeratins in oocytes and eggs of the frog Xenopus. Proc Natl Acad Sci U S A. 1983 Oct;80(20):6254–6258. doi: 10.1073/pnas.80.20.6254. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Geisler N., Kaufmann E., Fischer S., Plessmann U., Weber K. Neurofilament architecture combines structural principles of intermediate filaments with carboxy-terminal extensions increasing in size between triplet proteins. EMBO J. 1983;2(8):1295–1302. doi: 10.1002/j.1460-2075.1983.tb01584.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Geisler N., Weber K. The amino acid sequence of chicken muscle desmin provides a common structural model for intermediate filament proteins. EMBO J. 1982;1(12):1649–1656. doi: 10.1002/j.1460-2075.1982.tb01368.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Godsave S. F., Wylie C. C., Lane E. B., Anderton B. H. Intermediate filaments in the Xenopus oocyte: the appearance and distribution of cytokeratin-containing filaments. J Embryol Exp Morphol. 1984 Oct;83:157–167. [PubMed] [Google Scholar]
- Hanukoglu I., Fuchs E. The cDNA sequence of a human epidermal keratin: divergence of sequence but conservation of structure among intermediate filament proteins. Cell. 1982 Nov;31(1):243–252. doi: 10.1016/0092-8674(82)90424-x. [DOI] [PubMed] [Google Scholar]
- Hoffmann W., Franz J. K. Amino acid sequence of the carboxy-terminal part of an acidic type I cytokeratin of molecular weight 51 000 from Xenopus laevis epidermis as predicted from the cDNA sequence. EMBO J. 1984 Jun;3(6):1301–1306. doi: 10.1002/j.1460-2075.1984.tb01966.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jorcano J. L., Magin T. M., Franke W. W. Cell type-specific expression of bovine keratin genes as demonstrated by the use of complementary DNA clones. J Mol Biol. 1984 Jun 15;176(1):21–37. doi: 10.1016/0022-2836(84)90380-2. [DOI] [PubMed] [Google Scholar]
- Kim K. H., Rheinwald J. G., Fuchs E. V. Tissue specificity of epithelial keratins: differential expression of mRNAs from two multigene families. Mol Cell Biol. 1983 Apr;3(4):495–502. doi: 10.1128/mcb.3.4.495. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lazarides E. Intermediate filaments: a chemically heterogeneous, developmentally regulated class of proteins. Annu Rev Biochem. 1982;51:219–250. doi: 10.1146/annurev.bi.51.070182.001251. [DOI] [PubMed] [Google Scholar]
- Lipman D. J., Pearson W. R. Rapid and sensitive protein similarity searches. Science. 1985 Mar 22;227(4693):1435–1441. doi: 10.1126/science.2983426. [DOI] [PubMed] [Google Scholar]
- Maxam A. M., Gilbert W. Sequencing end-labeled DNA with base-specific chemical cleavages. Methods Enzymol. 1980;65(1):499–560. doi: 10.1016/s0076-6879(80)65059-9. [DOI] [PubMed] [Google Scholar]
- Mohun T. J., Brennan S., Dathan N., Fairman S., Gurdon J. B. Cell type-specific activation of actin genes in the early amphibian embryo. Nature. 1984 Oct 25;311(5988):716–721. doi: 10.1038/311716a0. [DOI] [PubMed] [Google Scholar]
- Moll R., Franke W. W., Schiller D. L., Geiger B., Krepler R. The catalog of human cytokeratins: patterns of expression in normal epithelia, tumors and cultured cells. Cell. 1982 Nov;31(1):11–24. doi: 10.1016/0092-8674(82)90400-7. [DOI] [PubMed] [Google Scholar]
- Newport J., Kirschner M. A major developmental transition in early Xenopus embryos: I. characterization and timing of cellular changes at the midblastula stage. Cell. 1982 Oct;30(3):675–686. doi: 10.1016/0092-8674(82)90272-0. [DOI] [PubMed] [Google Scholar]
- Newport J., Kirschner M. A major developmental transition in early Xenopus embryos: II. Control of the onset of transcription. Cell. 1982 Oct;30(3):687–696. doi: 10.1016/0092-8674(82)90273-2. [DOI] [PubMed] [Google Scholar]
- Okayama H., Berg P. A cDNA cloning vector that permits expression of cDNA inserts in mammalian cells. Mol Cell Biol. 1983 Feb;3(2):280–289. doi: 10.1128/mcb.3.2.280. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Perlman S., Rosbash M. Analysis of Xenopus laevis ovary and somatic cell polyadenylated RNA by molecular hybridization. Dev Biol. 1978 Mar;63(1):197–212. doi: 10.1016/0012-1606(78)90125-2. [DOI] [PubMed] [Google Scholar]
- Sagata N., Shiokawa K., Yamana K. A study on the steady-state population of poly(A)+RNA during early development of Xenopus laevis. Dev Biol. 1980 Jun 15;77(2):431–448. doi: 10.1016/0012-1606(80)90486-8. [DOI] [PubMed] [Google Scholar]
- Sargent T. D., Dawid I. B. Differential gene expression in the gastrula of Xenopus laevis. Science. 1983 Oct 14;222(4620):135–139. doi: 10.1126/science.6688681. [DOI] [PubMed] [Google Scholar]
- Steinert P. M., Parry D. A., Racoosin E. L., Idler W. W., Steven A. C., Trus B. L., Roop D. R. The complete cDNA and deduced amino acid sequence of a type II mouse epidermal keratin of 60,000 Da: analysis of sequence differences between type I and type II keratins. Proc Natl Acad Sci U S A. 1984 Sep;81(18):5709–5713. doi: 10.1073/pnas.81.18.5709. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Steinert P. M., Rice R. H., Roop D. R., Trus B. L., Steven A. C. Complete amino acid sequence of a mouse epidermal keratin subunit and implications for the structure of intermediate filaments. Nature. 1983 Apr 28;302(5911):794–800. doi: 10.1038/302794a0. [DOI] [PubMed] [Google Scholar]